1. Field of the Invention
The present invention relates generally to a spool assembly for carrying strand or ribbon-like materials such as wire, chain and rope etc. which material is unwound from the spool assembly when it is to be sold or used.
Each spool assembly must be constructed so that it can be supported upon brackets to permit free rotation when unwinding the material. The invention is specifically directed to a knockdown spool assembly of the type having spaced end plates and an elongated spindle connecting the end plates. A locking arrangement member is located on each end of the spindle and is engageable with a locking arrangement formed on an end plate when the spool is assembled. Spool assemblies of this type are shipped in the knocked-down condition and are assembled by the purchasers. This results in less expensive shipping costs. It is essential that the connections between the spindle ends and the end plates permit easy and rapid assembly of the spool and also firmly connect the end plates with the spindle to ensure that the material wound on the spool assembly is maintained on the spool assembly until the material is unwound.
Spool assemblies of the type to which this invention is directed are used in large quantities by both manufacturers and users of strand material such as wire, chain and rope etc. This type of spool is commonly formed from synthetic resin compounds or plastics. The strength required of the spool determines to a certain extent the material from which the end plates and the spindle are made, as well as the dimensions of those pieces. The spool assembly must have sufficient strength to withstand normal handling as occurs in winding, unwinding and shipping without breakage. It has been found that the following materials may be advantageously utilized to form the elements of the spool assembly of the present invention, polyacrylate, high density polyethylene, polyurethane, polyvinyl chloride or polybutadiene-urethane.
2. Related Prior Art
This application is directed to an improvement upon the invention disclosed and claimed in U.S. Pat. No. 4,903,913 granted Feb. 27, 1990 and entitled "Knock-Down Spool Assembly". That patent is owned by the assignee of the instant application and discloses a spool assembly having end plates attached to opposite ends of a spindle by a snap connection arrangement similar to the arrangement utilized in the instant application. The disclosure of Pat. No. 4,903,913 is incorporated herein by reference.
U.S. Pat. No. 4,128,215 discloses a spool having spaced end plates with plugs which are inserted into the ends of a hollow spindle. Each plug includes a flange and a tongue element. The tongue has raised projections positioned for engagement with openings in the spindle. This arrangement provides for the end plates to be locked to the spindle.